I recommend carrying one of these slime kits around.
https://www.ebay.co.uk/itm/Toyota-Al...53.m1438.l2649
I have used them in the passed and they seem to work OK.
It's worth remembering some breakdown services such as the "AA" will not recover you if you do not have a spare wheel.
As far as I am a were one of these types of repair agent will satisfy their requirement and they'll recover you if it fails to do the job.
Just make sure the can of sealant is in date.